I found these six darlings in an untitled notepad
1) Thundercracker was formerly a musician, thus his sonic boom.
2) Instead of Bumblebee meeting Sam, it was Cliffjumper.
3) Sideswipe and Sunstreaker do a personality switch, but their ethics and morals are still the same. Thus a more violent and vain Sideswipe, but still essentially the same prankster personality. On the flip Sunstreaker is still extremely aggressive/violent but now has a deceiving demure of friendly prankster.
4) Skyfire is normally kept at a friendly distance because of his past with Starscream, but a moment of vulnerability in public reminds them (the Ark, Decepticons, both) what once was and what they are fighting for.
5) One of the Dinobots (G1) falls into the past before/during the golden age. There they meet a youngling Ratchet who's meek and unsure of himself. Taking the youngling under his wing the dinobot raises/mentors Ratchet into the force he is today (before dying, thus preventing time traveller Dinobot from meeting himself in the future).
6) TF:A Prowl dies but is brought back by the Allspark into the Bayverse. Unfortunately his lithe model makes him a femme in this world. The motorcycle alt mode doesn't help.